The dataset contains all essential computational results that support the results of the combined 
electrochemical, X-ray and Raman spectroscopic study of mackinawite and mackinawite nanoparticle 
redox interconversion to a previously unreported phase with BOTH ferric ion (metal-based oxidation) 
and disulfide ion (ligand-based oxidation)in a yet to be refined composition.

All calculations were carried out using the S K-edge X-ray absorption spectroscopy validated hybrid 
density functional theory containing 5% HF exchange and employing triple-zeta quality basis set with 
polarization functions DOI: 10.1002/jcc.20449 and DOI: 10.1002/jcc.24384). 
In order to avoid artifactual differences due to the charge state changes upon redox, all models 
were embedded into SMD polarizable continuum model (https://comp.chem.umn.edu/solvation/) with s
tandard water parameters. 

The EXPERIMENTAL DATA reported in the main text is deposited here, where the names of the samples 
correspond to the experimental conditions. Further information concerning the preparation method 
and data acquisition can be found in the Materials & Methods/Results & Discussion section. 

RAMAN SPECTROSCOPY:
The raw data for the electrochemically oxidized FeS and reference samples can be found in the 
FeS_Raman.xlsx file. The spectrometer was calibrated against crystalline silicon for all samples, 
and for long measurements additionally calibrated internally against the laser line at 0 1/cm.
When the laser line at 0 1/cm was found to be drifting, a correction of 5 1/cm was applied to 
the corresponding sample before averaging of different measurement locations into the average 
spectra shown in the main text. 

X-RAY ABSORPTION NEAR-EDGE SPECTROSCOPY:
The raw data for the sulfur K-edge spectra is deposited in "FeS_XANES.xlsx". 
The normalized spectra (and their derivatives) were created using ATHENA (see at
https://bruceravel.github.io/demeter/documents/Athena/index.html).

VOLTAMMETRY:
The voltammograms of FeS, FeCl3 and FeS+Sn2- in 200 mM phosphate buffer with scanning speed of 10 mV/s
are located in the file "FeS_PO4_voltammetry.xlsx" 


File extensions:
==================
fchk - formatted Gaussian16 checkpoint files (technical details of calculations)
out - Vibrational analysis of stationary structure (IR + Raman intensities)
xyz - Xmol formatted Cartesian atomic positions
ods - OpenOffice spreadsheet files
odp - OpenOffice presentation files
pdf - Portable document format files
ppt - MS powerpoint slides
xls - MS excel spreadsheet

Folder structure:
==================

xrd-based_models: 
	utilizing the only 2Fe-2S molecular cluster with polysulfide ligands (CCDB code RENGIA - 
	DOI:10.1107/S0108270197099484) and exploring how oxidation state changes and protonations 
	effect the structure and Raman spectroscopic features.

combinatorial_models:
	combinatorial study of systematic variation of S, O ligand composition, protonation state, 
	iron ion redox chemistry.

core_extraction:
	templates for generating the [2Fe-2S] core spectrum (IR + Raman intensity + Raman activity)
	tutorial and worked out examples 

[2Fe-2S]_Raman:	
	demonstrative workout example for core extraction procedure using simplest 2Fe-2S/2Fe-2SSH 
	rhombs.

fragments_for_merging:
	source code and the in-house code to construct well-defined ionic valence-bond limit 
	structures for [Fe-S] clusters, as described in DOI: 10.1002/jcc.20449

maxkinawite_nanoparticles
	combinatorial study of [8Fe-8S] flat cluster ([2Fe-2S] inner rhomb surrounded with [6Fe-6S] 
	peripheral ring) embedded with various disulfide, polysulfide, bisulfide termination in
	*red*uced ([2Fe(II)-2S] inner rhomb), *mix*ed valence ([Fe(II)Fe(III)-2S]+ inner rhomb), 
	and *oxi*dized ([2Fe(III)-2S] inner rhomb). Predicted Raman spectra are shown in the PPT files.

2Fe2S-FeSSFe
	computational results used to generate the interconversion potential energy surface (Fig.7)
	with conserved stoichiometry following separate two-electron metal and ligand-centered redox 
	rearrangements